1. Field of the Invention
The device of this invention resides in the area of plumbing tools and more particularly relates to a tool that stops fluid flow in a pipe to an area of such pipe where soldering is to occur, such tool having a balloon-like structure at one end thereof that inflates within the pipe for blocking fluid flow and upon deflation, allows fluid to pass.
2. History of the Prior Art
A well known problem in soldering plumbing pipes is the difficulty in achieving good soldering joints when water is still draining through the pipes. Water draining from upstream locations often interferes with soldering and in the past efforts have been made to prevent such water flow, such as by plugging the pipe above the area of soldering or even by freezing the pipe which causes frozen water in the pipe to form a plug to block water flow. Over the years other devices have been developed to temporarily stop such water flow such as by inserting a removable plug into the pipe to be soldered.
It is an object of this invention to provide a plumbing tool for temporarily plugging a pipe to prevent water flow to a portion of a pipe where soldering is to occur. The device of this invention also provides an inner water escape tube for water drainage beyond the area of soldering while preventing any water flow through the pipe that might prevent the formation of a good solder joint. The device of this invention further compensates for irregular surfaces on the inner walls of older pipes that often form due to mineral deposits.
A tube member is provided comprised of an outer tube through the length of which a longer inner water escape tube passes. The first end of the tube member is inserted into the opening of a pipe to be soldered which tube member is flexible and can pass easily through the opening of any fitting that is to be soldered to the end of the pipe. Once the first end of the tube member is in place, a deflated balloon-like structure, herein referred to as a balloon, which is disposed around the first end of the tube member is inflated from an air supply unit attached to the second end of the tube member, such air supply unit containing a piston, until the balloon makes water-sealing contact with the inside wall of the pipe, thereby blocking further water flow down the pipe.
The air supply unit is composed of a cylinder in which is disposed a piston and attached piston shaft. A first cylinder cap is disposed at the first end of the cylinder, and a second cylinder cap is disposed at the second end of the cylinder. A piston handle is attached to the piston shaft beyond the second end of the cylinder. At least one O-ring can be disposed around the piston to create an airtight seal with the inner wall of the cylinder. The second end of the outer tube is attached to the first cylinder cap. An airtight air chamber is defined in the first cylinder cap between the piston, the inner walls of the first cylinder cap and the second end of the outer tube. The second end of the inner water escape tube passes through the air chamber and exits through an inner water escape tube aperture in the first cylinder cap into which aperture the inner water escape tube is engaged in an airtight fashion. The area between the outer tube and the inner water escape tube forms an air channel therebetween. Air pressure exerted on air in the air chamber is in communication with the air channel within the tube member. An air aperture at the first end of the outer tube allows air to pass from the air channel into the balloon. The piston moves within the cylinder by action on a piston handle attached to the piston shaft which piston shaft extends out of the second cylinder cap such that by movement of the piston handle, the piston shaft and attached piston can be moved back and forth within the cylinder. The O-ring(s) around the piston create an airtight seal such that piston movement in the direction of the first cylinder cap pressurizes air within the air chamber which passes pressurized air through the air channel to the air aperture(s) located at the first end of the outer tube, causing such pressurized air to inflate the balloon which is placed in the desired position within the pipe. In some embodiments the piston shaft can be threaded within the second cylinder cap with mating threads disposed in the second cylinder cap to allow for rotational movement of the piston handle to accurately control of the expansion or contraction of the balloon. The balloon of this invention, since it is not rigid or fixed in diameter, will conform as it expands radially to any surface irregularity present on the inside of the pipe to afford a complete seal to any water flow. The inner water escape tube at its first end has a water escape tube opening to receive water coming from upstream of the balloon that is plugging water flow in the pipe such that upstream water passes into the inner water escape tube opening and through the inner water escape tube to the point where such inner water escape tube passes through the water escape tube aperture formed in the first cylinder cap to the inner escape tube""s exit opening and the water can drain out such opening at the second end of the inner water escape tube. A removable cap can be applied to the exit opening at the end of the water escape tube.
When one wishes to disengage the plumbing tool of this invention from the pipe, one maneuvers the piston handle in a direction which moves the piston rearward, reducing air pressure in the air chamber and air channel which action then pulls air back through the air aperture(s) to cause the deflation of the balloon. The tube member including the outer tube and inner water escape tube can then be pulled out of the pipe.